Automatic response function general messaging systems, computerized systems, are designed to process incoming calls from pay or non-pay calling stations. Such systems are typically accessed and controlled through a telephone line. An incoming call is received from the telephone system and processed by the general message system computer, or processing may be initiated by the telephone system computer. Processing procedures may prompt the caller to select a desired service by pressing numeric keys on the telephone keypad. Selection of a service causes the service provider computer to typically continue processing the call, or the message system computer may process the call and store the message for later delivery to the selected service.
The identity of each numerical key is determined from an analog, dual tone multifrequency signal (DTMF) which is generated upon depressing the numerical key. The DTMF is a combination of two analog voice frequency tones, and it addresses stored digital code. Timing is typically not critical in the entry of DTMF signals for the identification of the numerals of standard, numerical keys. The telephone system computer, or the message system computer, converts the analog DTMF tones into digital signals for processing. The computer may also convert digital signals into analog voice signals for providing acknowledgement/prompt messages to the caller.
For example, by pressing the numeral 1 on the keypad in response to a computerized voice prompt, the caller may be connected from a messaging computer to a computer for a facsimile machine.
Computerized telephone systems and general message systems, typically file servers, may also eliminate voice communication and require the caller to communicate exclusively through the telephone keypad. In one such application wherein a caller desires that information be delivered by facsimile, the caller may press the number key corresponding to the number of the desired document and, upon entry of the start button or the receiving facsimile number, the document will be delivered.
Entry of the letters of the alphabet is desirable for communicating with automatic response function general messaging systems. For example, the caller's name, address, and/or code number are desirable information for input to a remote pager, a facsimile message, an E-Mail message system, or a bank computer to obtain an account balance.
The universally recognized standard for the push button telephone keypad is a 4.times.3 matrix having four rows and three columns of buttons, or keys. Each key is preassigned with a single digit or special symbol as a primary assignment, and with three alphabetic characters as a secondary functional assignment. While the universally recognized 4.times.3 keypad of the prior art standardizes the physical arrangement of the numeric characters, the physical arrangement of alphabetic characters may vary. One typical push button telephone matrix of the prior art includes twenty four letters of the alphabet, excluding the "Q" and the "Z" arranged on eight of the twelve keys as follows:
______________________________________ KEY 1 No letters KEY 2 ABC KEY 3 DEF KEY 4 GHI KEY 5 JKL KEY 6 MNO KEY 7 PRS KEY 8 TUV KEY 9 WXY KEY 0 No letters KEY * No letters KEY # No letters ______________________________________
There are several methods of entering alphabetical characters using the conventional telephone keypad design outlined above. With the exception of Applicant's co-pending U.S. patent application No. 07/500,370, none of the methods provide for the DTMF signal entry of alphabetical characters, and timing of entry is critical in the first prior art method.
The first method requires the caller to locate the desired letter on the telephone keypad and to press the corresponding key either once, twice, or three times, depending upon the location of the desired letter on the key, followed by pressing an additional symbol key, such as the pound sign key, which operates as a signal code to indicate the desire to enter a character as opposed to a digit. This method is shown in the Hashimoto et al. U.S. Pat. No. 4,658,417. For example, to enter the name "JONES" using the Hashimoto method, the following steps are required:
______________________________________ "J" KEY 5 Press once # KEY Press once "O" KEY 6 Press three times # KEY Press once "N" KEY 6 Press two times # KEY Press once "E" KEY 3 Press two times # KEY Press once "S" KEY 7 Press three times # KEY Press once ______________________________________
The first method does not permit the caller to enter digits and letters within the same word. The method is time critical in that pressing the Number 2 key three times in a row could provide for the input of the letters C, or AB, or BA, or AAA depending upon the timing between keystrokes. Because the number of keystrokes used to enter letters is not constant and a separate symbol key must be pressed before entry of the next desired letter, the caller is required to provide considerable concentration to correctly complete the desired entry.
A second method for entering letters of the alphabet requires the caller to locate and press the key bearing the desired letter and then to press the key bearing the numeral corresponding to the position of the desired letter on the key. For example, to enter the letter "H" the caller must first press the number four key which bears the letter "H", and must then press the number two key because the "H" is the "second" letter on the number four key. The following steps are required to enter the name "JONES" using the second method:
______________________________________ KEY 5 Press once KEY 1 Press once (Pause) KEY 6 Press once KEY 3 Press once (Pause) KEY 6 Press once KEY 2 Press once (Pause) KEY 3 Press once KEY 2 Press once (Pause) KEY 7 Press once KEY 3 Press once ______________________________________
Although the second method standardizes the number of keystrokes for each letter, it requires considerable concentration by the caller to properly complete the required keystrokes.
Applicant's co-pending U.S. patent application No. 07,500,370, filed on Mar. 28, 1990, now U.S. Pat. No. 5,117,455, issued on May 26, 1992, describes a novel method and apparatus for entering characters into a telephone system using a conventional telephone keypad. The method and apparatus described therein are suitable for using a telephone keypad as a data terminal to provide information to any messaging computer for delivery to a service provider computer, such as paging system computers, E-Mail system computers, facsimile equipment, bank computers, information depository computers, etc.